No missing sink: Estimates of the flux of microplastics from rivers, in the context of the mass of plastic that has been observed in the ocean, have made it appear that a large, unidentified sink of plastics must exist there. Weiss et al. show that there may not be a missing sink after all. By reformulating how mass fluxes are calculated from observations of particle numbers, they demonstrate that those mass fluxes were overestimated by two to three orders of magnitude. This explains why the residence time of plastics in the ocean seemed so puzzlingly short and implies that ocean plastics may persist and degrade over longer periods than previously thought. Science , abe0290, this issue p. 107